‘Svchost’ overload.. I dont know what else to do, can some one help?

I’ve just recently installed windows vista Ultimate RTM version and for some reason I have 12 ‘svchost’ processes all running at the same time… and almost completely consuming all of my memory. I’ve tried various anti spy/ad ware programs but none of them seem to work. Registry cleaning software does nothing also… how can I optimize my system? Also, I ran a “Hijack-this” scan and noticed a bunch of ‘file missing’ entries but im not sure weather or not I can delete these. Please advise. I appreciate any help help.

Vista takes control above all memory for better control, then it assigns it to programs.
So lets say, that you have 1024 MB and Vista takes 1000 MB, it is completelly normal.
Of course, if you have 256 MB, that is another story, in that case look at Vista Guide.